Genetic and morpho-physiological attributes of drought resistance in Capsicum accessions

Abstract

Drought stress is one of the factors limiting pepper production in water-stressed regions. It affects growth and development by inducing morphological, biochemical, and physiological changes. Breeding drought-resistant varieties is a sustainable strategy to mitigate drought, therefore, reliable evaluation systems are essential to identify drought-resistant pepper accessions. In this study, 100 pepper accessions were screened for drought resistance under highly controlled conditions at the vegetative stage. Selected accessions exhibited a significantly higher recovery rate after water-deficiency and showed durable resistance under greenhouse conditions. Correlation analysis between drought resistance with morphological and physiological traits showed that the recovery rate was positively correlated with root length and relative water content, and negatively correlated with plant height and leaf area. Gene expression analysis showed that the drought-resistant accession exhibited higher expression levels of drought-responsive genes under drought stress. Among the accessions, anthocyanin-accumulating peppers showed more significant drought resistance compared to other accessions. When the MYB transcription factor An2, the genetic determinant of anthocyanin accumulation, was silenced, drought resistance was significantly reduced. Drought-resistant accessions with favorable adaptive traits identified in this study will be valuable in various breeding programs to generate new pepper cultivars to cope with climate change.